Motor lawn-mower.



W. H. COLDWELL.

MOTOR LAWN MOWER.

APPLIGATION FILED JUNI: 21, 1910.

1,012,521, Patented Dec.19, 1911.

3 SHEETS-SHEET 1.

INVENTOR lzeyo W. H. COLDWELL.

MOTOR LAWN MOWER.

APPLIUATION FILED JUNE 21, 1910l 1,012,521. Patented Dec. 19,1911.

3 SHEETS-SHEET 2. 42

H. COLDWELL, 0F NEWBUBGH NEW YORK.

MOTOR LAWN-MOWBR.

Specification of Letters Patent.

PatentedDec. 19, 1911.

Application tiled J'une 21, 1910. Serial No. 568,195. l

To all whom it may concern:

Be it known that I,.W11.LIAM H. COLD- WELL, citizen of the UnitedStates, residing at Newburgh, in the county of Orange and State of NewYork, have invented certain new and useful Improvements in MotorLawn-Mowers; and I do hereby declare the following to be a full, clear,and exact description of the invention, sch as will enable othersskilled in the art to which it appertains Vto make and use the same.

My invention consists in the novel features hereinafter' set forth,reference bein had to the accompanying drawings which i lustrate oneform in which I have embodied the same and the invention is fullydisclosed in the following description and claims.

Referring to the said drawings, Figure 1 represents a side elevation ofa motor lawn mower having my invention embodied therein. Fig. 2 is aplan view of a portion of the power transmitting mechanism of themachine showing the embodiment of my invention which I have selected forpurposes of illustrating the invention. Fig. 3 represents a verticalsection on line 3-3 of Fig. 2. Fig. 4 is an enlarged perspective view ofthe female member of the friction clutch. Fig. 5 is a similar view ofthe male member, of the friction clutch and one member of the positiveclutch. Fig. 6 is an enlarged horizontal section on the line 6-6 of Fig.3.

In the operation of lawn mowers and particularly motor lawn mowers, itfrequently happens that the revolving cutter .is stopped, as by a stickor stone lodging between a blade of the rotary cutter and the stationaryknife bar, or otherwise, in which case, some part of the mechanism isliable to be injured. This is particularly the case in motor driven lawnmowers, Where owing to the large amount of power available, such an'accident is likely to break the chain or other gearing transmittingmotion to the revolving cutter. Y

The object of myinvention is to provide means whereby the revolvingcutter may be stopped instantly without causing any injury to themechanism for driving the same, and to combine therewith means fornotify ing the operator that the cutter has been stopped, in order thathe may shut olf the power and remove the obstruction which has causedthe stoppage, and further to provide a device of this character whichcan be accurately adjusted to produce the `desired re'- sult, and whichwill not be affected in its operation by the operation of throwing theclutch mechanism connecting it with the source of power, into or out ofoperation.

In the embodiment of the invention herein nism may also beadvantageously used in' other types of lawn mowers,` or motor lawnmowers, and in 'other kinds of. machinery as well.

In Fig. 1 I have shown a side elevation of a Coldwell motor lawn mower,in which 1 represents the motor truck or frame supported uponthetraction 'and lawn rolling rollers 2 and the steering. roller 3. Themower frame which is indicated at 4, is propelled in front of the motorframe by loosely jointed push arms 5, 5, and carries the usualstationary cutter and the rotary cutter 6, the shaft of which isindicated at 6. 7 represents the driving shaft of 'the machine, which isconnected with a suitable motor, and is directlyconnected with the shaft6 of the rotary cutter by sprocket chains 8 and 9, the chain 8 engaginga sprocket 10, on the driving shaft, and one of a pair of connccted'idle sprocketsl 11, 11, mounted on a stud concentric with the pivotalconnection of the arms 5 with the motor frame, and the chain 9 engagesthe other sprocket 11 and a sprocket 12 on the shaft of the rotarycutter. This arrangement permits the mower frame to rise and fall withrespect to themotor frame without disturbing the driving connections,and the loose connections of the arms 5 with the motor frame and mowerframe permits the mower frame to rock transversely and longitudinallywith respect to lthe motor frame to accommodate itself to variations inthe surface of the ground. The driving shaft is connected with a secondmotion shaft 13, by a sprocket chain 14, and the shaft 13 is connectedby chain 15`with the traction and lawn rolling rollers, which are drivenat a slower speed than the revolving cutter.

Referring now to Figs. 2 to 6 inclusive, the

'driving shaft 7 is provided with a. loose 23 and a friction rim orflange 24 having llO its interior coned and forming a friction surface.The clutch member 21 is secured to (or has formed integrally with it)the driving sprocket 10 for operating the rotary cutter, and is capableof slight movement longitudinally of the shaft. 25 repre-A sents theother member of the friction clutch, which is rigidly attached to thesleeve 2O and consists of a casting having a conicalperipheral frictionface to fit within the clutch member 21. I also secure rigidly to thesleeve 20 one member of a posi-l tive clutch shown at 26, provided withteeth or projections 27. ln this instance the clutch member 2G isriveted to the'cone 25, and the two clutch members 25 and 26 are rigidlysecured to the sleeve by means of a nut 28 screwed on a threaded ortionat one end of the sleeve, and clampmg the clutch members between it andan annular rib 29 with which the sleeve is provided. .The

other end of the sleeve is provided with an adjusting nut 30 on athreaded portion of the sleeve7 and a spiral spring 31 is interposedbetween the adjusting nut and the sprocket 10 and clutch'member 21.- Byadjusting the nut 30, the frictional resistance between the clutchmembers 21 and 25 can be accurately adjusted, and the nut 30 is 1 beensecured.

4provided with locking means for` securing itin adjusted. position. Inthis instance they nut 30 is provided with a recess on its interior, inwhich is fitted a clamping plate 32, threaded on its inner side toconform with the threading of the nut, and this plate is clampedagainst'the threaded portion of the sleeve- 2O by set screw 33, when thedesired adjustment of the spring has 34 represents the movable member ofthe positive clutch, mounted on the shaft 7, so as to turn therewith butmovable longitudinally thereof, being in this instance connected to theshaft by a key or feather 34a, and provided with teeth or projections 35to engage those of the fixed clutchmember 26 and with an annular groove36 to `receive studs 37 on a yoke 38, pivoted at 39 and having an arm 40extending rearwardly toward the driver7s seat. For convenience inloperating the positive clutch from the driver-s seat, the arm 40 isprovided at its rear end with a yoke 41, engaging the lower end of apivoted verti- I cally disposed hand lever 42. rl`he sleeve tions isentirely obviated.

example the collars 43, 44, the latter of which is placed at the innerend of the sleeve between the two members of the positive clutch. It isto be noted that with the single exception of the clutch member 34, theapparatus is entirely supported upon the sleeve 20, and is thereforewhat might be termed self contained and the "appa` rat-us can be placedin position upon any by the tension of the spring 31, and its ad-4justing nut 30, and cannot be increased orafected in any way by theoperator in throwing the positive clutch into and out of operation. lnorder to provide means for calling the operators attention to the factthat the friction clutch is slipping, for any reason as by theobstruction or clogging of the rotary cutter, I provide 'the frictionclutch member 25 with a .'yielding-fprojec` tion, in line with theannular row of teeth or serrations 23 in the clutch member 21. in thisinstance l have shown the part 25 provided with a transverse aperture inline with said teeth 23, in which is locateda loose pin 45, the outerend of which is engaged by a -spring plate 46 (see Figs. 5 and 6)secured in place by a screw 47, which is conveniently provided with alocking washer 48 to prevent it from unscrewing, a split spring washerbeing suitable for this purpose. j

ln the operation of the device the spring 31 will be adjusted to providesufli'cient friction between clutch members 21 vand 25 to overcome anyordinary resistance of the rotary cutter, in normal operation. Ify thecutter encounters any abnormall resistance, as by the lodgment of astick or stone, etc., the resistance of the friction surfaces will beinstantly overcome, and the cutter will remainstationary while thelshaft 7 continues to revolve, and the pin 45 in passing over the teethor serrations 23, will set up a noise which will `at once notify theoperator, who will proceed Ito stop the machine and remove the cause ofthe trouble. By this means the danger of breaking or injuring the rotarycutter yor its driving connec- As the members of the friction clutch arenever given relative movement except in dependent of the mechanism forpropelling the machine over the ground and is, therefore, not affectedin any way by said propelling mechanism.

What I claim and desire to secure by Letters Patent is 1. In a motorlawn mower provided with a motor, propelling mechanism and cuttingmechanism including a rotary cutter, the combination with the rotarycutter, of a friction drive therefor comprising a driving shaft, a fixedfriction clutch member loosely mounted on but held `from longitudinalmovement with respect to said shaft, a movable friction clutch memberloose on the shaft, and movable longitudinally thereof, a springsurrounding said shaft and holding said clutch members in engagementwith`a predetermined pressure, a .connection between said movablefriction clutch member and the rotary cutter, and a separate clutch, forthrowing the cutter into and out of operation, having a fixed memberloosely mounted on the shaft and rigidly secured to the fixed frictionclutch member, and a movable member secured to the shaft to rotatetherewith but movable longitudinally of the shaft whereby the cutter canbe thrown into and out of engagement without affecting the relation ofthe friction clutch members.

2. In a motor lawn mower provided with a motor, propelling mechanism andcutting mechanism including a rotary cutter, -the combination with therotary cutter, of a friction drive therefor comprisingA a driving shaft,a fixed friction clutch member loosely mounted on but held fromlongitudinal movement with respect to said shaft, a movable frictionclutch member loose on thev shaft, and movable longitudinally thereof, aspring surrounding said shaft and holding said clutch members inengagement with a predetermined pressure, a connection between saidmovable friction clutch member and the rotary cutter, and a separateclutch for throwing the cutter into and out of operation, having a fixedmember loosely mounted on the shaft and rigidly secured to the fixedfriction clutch member, and a movable member secured to the Shaft torotate therewith 'but movable longitudinally of the shaft, .saidfriction clutch members being provided the one with a serrated portionand the other with a movable part for engaging said serrated portion.

3. In a motor lawn mower provided with a motor, propelling mechanism andcutting mechanism including a rotary cutter, the

combination with the rotary cutter, of a fric` tion drive for thecutterindependent of the -pro elling mechanism, comprising a driving sha tconnected with the motor, a sleeve loosely mounted on the shaft, afriction clutch member secured rigidlyeto said sleeve, a second frictionclutch mem r loose on the sleeve, land operatively connected with thecutter, a spring carried by the sleeve, for holding the clutch memberstogether with a predetermined pressure, a positive clutch member ri 'dlysecured to the first mentioned friction clutch member, and a secondpositive clutch member secured to rotate with the driving shaft, andmovable into and out of engagement with the' other positive `clutchmember.

In testimony whereof I ailix my signature, in the presence of twowitnesses.

WILLIAM H. ooLnwELL.

